Proguard警告：找不到引用的类Scala。*

Question

升级到新的Android工具后，我收到来自Proguard的以下警告：

Warning: scala.xml.EntityRef: can't find referenced class scala.xml.EntityRef$$anonfun$text$1
Warning: scala.xml.dtd.AttrDecl$: can't find referenced class scala.xml.dtd.AttrDecl$$anonfun$toString$1
Warning: scala.collection.mutable.LinkedListLike: can't find referenced class scala.collection.mutable.LinkedListLike$$anonfun$insert$1
Warning: scala.xml.NamespaceBinding: can't find referenced class scala.xml.NamespaceBinding$$anonfun$toString$1
Warning: scala.xml.NamespaceBinding: can't find referenced class scala.xml.NamespaceBinding$$anonfun$buildString$1
Warning: scala.xml.MetaData$: can't find referenced class scala.xml.MetaData$$anonfun$toString$1
Warning: scala.xml.MetaData$: can't find referenced class scala.xml.MetaData$$anonfun$toString1$1
Warning: scala.collection.immutable.BitSet: can't find referenced class scala.collection.immutable.BitSet$$anonfun$$plus$1
Warning: scala.collection.immutable.BitSet: can't find referenced class scala.collection.immutable.BitSet$$anonfun$$minus$1
Warning: scala.collection.mutable.FlatHashTable$$anonfun$checkConsistent$1: can't find referenced class scala.collection.mutable.FlatHashTable$$anonfun$checkConsistent$1$$anonfun$apply$mcVI$sp$1
Warning: scala.collection.immutable.RedBlack: can't find referenced class scala.collection.immutable.RedBlack$Empty
Warning: scala.collection.immutable.BitSet$: can't find referenced class scala.collection.immutable.BitSet$$anonfun$$plus$1
Warning: scala.collection.immutable.BitSet$: can't find referenced class scala.collection.immutable.BitSet$$anonfun$$minus$1
Warning: scala.xml.EntityRef$: can't find referenced class scala.xml.EntityRef$$anonfun$text$1
Warning: scala.Either: can't find referenced class scala.Either$$anonfun$joinLeft$1
... (more) ...

有什么提示为什么Proguard无法找到这些类？我怎样才能解决这个问题？

Answer 1

如果从scala-library.jar（版本2.9.1）中查看列出的类的内部结构，您会发现它们引用的类根本不存在。在我看来，这是一个编译器问题。但是，引用并不是处理和运行代码的基础，因此您可以使用以下选项让ProGuard接受jar：

-dontwarn scala.**